This invention relates to a method of automatically reattaching broken threads in spinning machines, as well as to an apparatus for performing this method.
Known thread attachment apparatus, such as the apparatus disclosed in U.S. Pat. No. 3,807,155 operates so that, in imitation of the manual techniques used by operators of spinning wheels and the like, the end of the broken thread is searched for on the bobbin or the spool and is grasped so as to be used in the actual attachment step of the method. This search for the end of the thread is a critical part of the entire thread breakage repair routine, because finding this thread end is difficult and often fails. If the end of the thread cannot be found, either because it cannot be loosened from the winding, or else because there is no thread present on the spool after a spool change, then the thread breakage cannot be repaired.
In order to avoid the above-mentioned disadvantage, it is provided in other known thread attachment apparatus, such as the apparatus disclosed in U.S. Pat. No. 3,591,951, that the end of the thread is not searched for on the bobbin or spool, but rather that another thread, a so-called auxiliary thread, is taken from a supply, carried by the attachment apparatus, and is "thrown" on the bobbin or spool, i. e., its end is wound up on the bobbin or spool. This thread can be grasped by the attachment apparatus and can be separated at a place between the thread arrester and the thread supply, i. e., it can be separated from the thread supply. The end of the thread thus obtained is then attached in the usual manner, i. e., after it is pulled into the traveler and the thread guide, it is joined to the roving sliver emerging from the delivery rollers. This technique has the disadvantage, however, that there is no connection between the broken thread and the reattached thread. When the thread is unwound in a subsequent operation, this becomes manifest as a thread breakage, i. e., at another machine.